diff options
author | Mark Pearson <markpearson@lenovo.com> | 2021-05-31 01:31:09 +0300 |
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committer | Hans de Goede <hdegoede@redhat.com> | 2021-06-16 18:47:51 +0300 |
commit | 17b707fe5fbd3c019691873c1c11bddb0e0f7225 (patch) | |
tree | f3a84c8296fc4c32e5c8cdf6b2e9978f086c353c /drivers/platform/x86/firmware_attributes_class.c | |
parent | 6cbaee2e109ed0f7327a2d3cbb412f36fd8873e0 (diff) | |
download | linux-17b707fe5fbd3c019691873c1c11bddb0e0f7225.tar.xz |
platform/x86: firmware_attributes_class: Create helper file for handling firmware-attributes class registration events
This offers shared code for registering the firmware_attributes_class,
which is used by the Dell and Lenovo WMI management drivers.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/20210530223111.25929-1-markpearson@lenovo.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'drivers/platform/x86/firmware_attributes_class.c')
-rw-r--r-- | drivers/platform/x86/firmware_attributes_class.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c new file mode 100644 index 000000000000..d62ec3d71ede --- /dev/null +++ b/drivers/platform/x86/firmware_attributes_class.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +/* Firmware attributes class helper module */ + +#include <linux/mutex.h> +#include <linux/device/class.h> +#include <linux/module.h> +#include "firmware_attributes_class.h" + +static DEFINE_MUTEX(fw_attr_lock); +int fw_attr_inuse; + +static struct class firmware_attributes_class = { + .name = "firmware-attributes", +}; + +int fw_attributes_class_get(struct class **fw_attr_class) +{ + int err; + + mutex_lock(&fw_attr_lock); + if (!fw_attr_inuse) { /*first time class is being used*/ + err = class_register(&firmware_attributes_class); + if (err) { + mutex_unlock(&fw_attr_lock); + return err; + } + } + fw_attr_inuse++; + *fw_attr_class = &firmware_attributes_class; + mutex_unlock(&fw_attr_lock); + return 0; +} +EXPORT_SYMBOL_GPL(fw_attributes_class_get); + +int fw_attributes_class_put(void) +{ + mutex_lock(&fw_attr_lock); + if (!fw_attr_inuse) { + mutex_unlock(&fw_attr_lock); + return -EINVAL; + } + fw_attr_inuse--; + if (!fw_attr_inuse) /* No more consumers */ + class_unregister(&firmware_attributes_class); + mutex_unlock(&fw_attr_lock); + return 0; +} +EXPORT_SYMBOL_GPL(fw_attributes_class_put); + +MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>"); +MODULE_LICENSE("GPL"); |